Earlier this year, I spent a week driving a preproduction Prius Plug-in hybrid, but little did I realize that Toyota was using me and the other people who got to drive the car as guinea pigs, test subjects to help further refine the car for a 2012 production model. Toyota recently put me behind the wheel of a substantially tweaked Prius Plug-in, this one the result of everything learned from the earlier drive program. Still billed as preproduction, this latest Prius Plug-in boasted enhancements over the previous car, along with a full-blown marketing strategy.

In typical Toyota fashion, this new preproduction car was not radically different than the one I drove previously. And I confess to a lack of enthusiasm over this new driving opportunity. Despite that you can plug it in, it is still just a Prius.

But that expectation crumbled a bit after seeing some of the improvements made to the car. And, like the previous version, it was a novel experience to drive a Prius at speed with the engine off.

During an initial presentation about the car, Toyota Vice President Bob Carter made it clear that the Prius brand would be a tent pole for the company. He talked up the four different models that will bear the Prius name: the original Prius liftback, Prius V, Prius C, and Prius Plug-in. A fan of the quick and maneuverable, I’m most looking forward to the Prius C, which will hopefully retain the sporty nature of its concept.

The presentation covered pricing for the car, which seemed high at $32,000, or $39,525 for a high-trim, fully loaded model. But that price is also subject to a $2,500 federal tax credit, bringing the base car under $30,000. Another journalist at the presentation suggested Toyota tailored the size of the Prius Plug-in’s battery pack, at 4.4 kilowatt-hours, to make the car qualify for the tax credit, which is based on battery capacity.

However, the earlier version of the Prius Plug-in I tested had a larger lithium ion battery, at 5.2 kilowatt-hours. The refined battery pack is smaller than that of the previous version, yet it gives the car more pure electric range, 15 miles versus 13 miles. Not a huge change, but 15 miles is a rounder number. Taking the gasoline tank into account, total range remains at over 500 miles.

Toyota also moved the charging port, as was shown by a model it had set up for photos showing the plug-in cable. Where it had previously been at the front fender, Toyota moved it to the right rear, the opposite side of the fuel tank filler. Nobody should have a problem pouring gasoline over the car’s plug, as the hatch cover also has an embossed plug symbol. Similar to the previous test model, charging times are rated at 3 hours for a 110-volt outlet, and 1.5 hours at a 220-volt outlet. Toyota is also partnering with Leviton to offer buyers a level 2 charger, which should take mere minutes to fill the battery.

Once handed the keys to this new, refined Prius Plug-in, I was pleased to note that the cargo area had been restored. Where the previous version’s battery pack caused a slight lift to the cargo load floor, the smaller battery pack in this preproduction model not only allowed a normal load floor level, but also an extra compartment for storing the charging cable.

The car started up, in Prius fashion, quietly. EV mode was already engaged and Toyota had charged the car up before this drive. But the range shown in the eyebrow display was only 11.8 miles, less than the promised 15. I wasn’t thrown by the lower number, as trip computers always calculate the range based on how the car was recently driven. Fleet drivers are not always gentle on the accelerator.

This Prius Plug-in glided quietly forward under quarter acceleration, lacking even the sound generator Toyota implemented on the Prius V model. Out on the first stretch of the 4.5-mile driving loop, I stepped into it, and the gas engine promptly fired up despite the still glowing green EV mode icon on the instrument cluster. Letting off acceleration, the engine persisted, ruining the promised electric drive experience. Pushing the EV mode button repeatedly turned the EV mode icon off and on, but didn’t shut off the engine.

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